com.google.mobile.trippy.web.client.Trippy.java Source code

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Here is the source code for com.google.mobile.trippy.web.client.Trippy.java

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/*
 * Copyright 2010 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.mobile.trippy.web.client;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.event.shared.HandlerManager;
import com.google.gwt.user.client.History;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.mobile.trippy.web.client.base.DefaultSingletonComponents;
import com.google.mobile.trippy.web.client.base.SingletonComponents;
import com.google.mobile.trippy.web.client.base.Utils;
import com.google.mobile.trippy.web.client.db.LocalDbService;
import com.google.mobile.trippy.web.client.db.TripService;
import com.google.mobile.trippy.web.client.event.ShowHomePageEvent;
import com.google.mobile.trippy.web.client.i18n.Message;
import com.google.mobile.trippy.web.client.widget.Toast;

import java.util.Date;

/**
 * Entry point for the class.
 *
 */
public class Trippy implements EntryPoint {

    //Sync db after every 60 secs.
    private static final int SYNC_PERIOD = 60000;

    private final SingletonComponents singletonComponent = new DefaultSingletonComponents();
    private HandlerManager eventBus;
    private static TripService tripService;
    private Toast toast;
    private Utils utils;
    private Message messages;

    /**
     * Entry point classes define <code>onModuleLoad()</code>.
     * 
     * Method acts as an entry point for the application.
     * 
     * The method initialize the necessary components in following sequence:
     * 1. Initialize Local DB and other components + Sync with Remote DB.
     * 2. Create Controller class.
     * 3. Bind Controller class for listening several Screen Level events.
     * 4. Create object of HistoryTokenHandler (ValueChangeHandler) over token 
     *    String. it will listen for Browser Back Button event.
     * 5. Adding above object to History.
     */
    public void onModuleLoad() {
        init();

        // Creating controller class and binding it for listening several Screen Level events.
        Controller controller = new Controller(singletonComponent);
        controller.bind();

        HistoryTokenHandler historyTokenHandler = new HistoryTokenHandler(singletonComponent);
        History.addValueChangeHandler(historyTokenHandler);

        String token = Window.Location.getHash().replaceFirst("#", "");
        if (token != null && token.length() > 0) {
            historyTokenHandler.showPageForToken(token);
        } else {
            eventBus.fireEvent(new ShowHomePageEvent());
        }
    }

    private void init() {
        eventBus = singletonComponent.getEventBus();
        tripService = singletonComponent.getTripService();
        toast = singletonComponent.getToast();
        utils = singletonComponent.getUtils();
        messages = singletonComponent.getMessage();

        // Expose methods to android shell app.
        AndroidProxy proxy = new AndroidProxy(eventBus);
        proxy.setDoSearch(proxy);

        final String cls = Window.Location.getParameter("cls");
        if (cls != null && cls.toLowerCase().equals("true")) {
            LocalDbService.clearDb();
        }
        initDb();

        utils.addOnlineHandler(new ValueChangeHandler<Boolean>() {
            @Override
            public void onValueChange(final ValueChangeEvent<Boolean> event) {
                if (event.getValue()) {
                    toast.showToast(messages.onLineStatusMsg());
                } else {
                    toast.showToast(messages.offLineStatusMsg());
                }
            }

        });

        utils.startCheckOnlineTimer();
        //    utils.startLocationUpdateTimer();

        toast.showLoading(messages.loading());
        syncFromRemoteDb(new AsyncCallback<Void>() {
            @Override
            public void onSuccess(Void result) {
                toast.hideLoading();
            }

            @Override
            public void onFailure(Throwable caught) {
                toast.hideLoading();
            }
        });

        final Timer timer = new Timer() {

            @Override
            public void run() {
                syncFromRemoteDb();
            }
        };
        // Sync db after every 60 secs.
        timer.scheduleRepeating(SYNC_PERIOD);
    }

    private void syncFromRemoteDb() {
        syncFromRemoteDb(new AsyncCallback<Void>() {
            @Override
            public void onSuccess(Void result) {
            }

            @Override
            public void onFailure(Throwable caught) {
            }
        });
    }

    private void initDb() {
        final String versionTime = getVersionTimestamp();
        final String serverVersion = getServerVersion();
        if (versionTime == null || serverVersion == null) {
            LocalDbService.clearDb();
            setVersionTimestamp(new Date().getTime() + "");
        } else if (versionTime.compareTo(serverVersion) < 0) {
            LocalDbService.clearDb();
            setVersionTimestamp(serverVersion);
        }
    }

    private native String getServerVersion() /*-{
                                             if (typeof($wnd.versionTime) === "undefined") {
                                             return null;
                                             }
                                             return $wnd.versionTime;
                                             }-*/;

    /**
     * Incremental sync from remote db to client db.
     */
    private void syncFromRemoteDb(final AsyncCallback<Void> callback) {
        tripService.syncFromRemoteDb(new AsyncCallback<Void>() {
            @Override
            public void onFailure(Throwable caught) {
                callback.onFailure(caught);
            }

            @Override
            public void onSuccess(Void result) {
                // TODO: Show message.
            }
        });
    }

    //TODO: make the string constant
    public static void setVersionTimestamp(final String versionTimestamp) {
        LocalDbService.makePersistent("app_version", versionTimestamp);
    }

    public static String getVersionTimestamp() {
        return LocalDbService.getPersistent("app_version");
    }
}